Mobile mixing and unloading vehicles are used to carry, mix and discharge a mixture of particulate materials to a location such as an animal feed lot. This equipment includes box or hopper structures for carrying the material. Rotating augers are located in the box structures to tumble and thoroughly mix the materials in the box and continuously move the materials. Conveyor structures are used to move the materials from the box to a desired location. The box structures have been mounted on trucks and trailers, permitting them to be moved along the feed bunk of a feed lot and discharge materials into the feed bunk. Examples of bulk material blending and unloading vehicles are shown in U.S. Pat. Nos. 2,885,191; 3,090,605; 3,189,202; 3,197,075; and 3,215,408.
Box-type material blenders have open tops to provide an access for loading the material into the box. The materials are loaded into the box with conveyors, buckets and other material handling equipment. Large portions of material, such as hard or frozen materials, and foreign objects, such as rocks and lumber, can be easily placed into the box. These objects, when dumped into the box, will place severe bending loads on the mixing structure in the box and will prevent the effective operation of the mixing structure. The open top box is also a hazard to the operator as there is no safety structure to prevent the operator from accidentally falling into the box and being injured by the mixing structure.
The maintenance and repair of the blending apparatus occasionally requires the removal of the mixing structure from the box. This requires considerable time and labor as the box structure must be disassembled in order to permit the removal of the mixing structure. The material blenders for agricultural livestock feeds are used as mobile units to place the blended feed in a feeding location, as a feed bunk. The blenders are also used as stationary units in feed mixing areas. The blended feed is carried by conveyor to a bunk feeder or like feeding structure. The box structures of the blenders must be altered to accommodate a vehicle or trailer structure or the same box structure is not used on a mobile unit and a stationary unit.